Does Vivarin effect your heart rhythm - also take Wellbutrin, Prozac and Yaz?

I take 400mg wellbutrin and 60 mg prozac daily. I also take yaz. Today I had a large coffee and took A vivarin tablet that was 200mg. I felt okay most of the day but now I am lying in bed and I feel my heart rhythm is abnormal. Whats going on? How bad is this and should I do anything about it?